Miniature fluid drill



April 2, 1963 s. R. KERN, JR

MINIATURE FLUID DRILL Filed Sept. 7, 1962 ill H h %\k m w" eh v fl mm mmmz wm Em \m N GP vm 0V\ QVN k mv 12 d .m 3 1- E P 224727? E [I I w 3N NNE sMM 1 Ill! Q q m fi \Qlll I I! flaw L 6501765 Ii. km; .m.

BY \M% QL ATTORNEYS United States This. invention relates. toimprovements 'in miniature fluid drills for various uses that'is. fluidpressure driven and is'a continuation-in-part of my.copending-application Serial No. 13,177, filed 'March 7, 196.0}.whichris to issue as.Patent 3;053,50 3,. issue date September 1-1,1962.

An object is to provide animprovedsmall handtype of drill that isofelongated slender shape for graspingin the hand and for manipulation by.the. fingersfwith fluid pressure motordrive. for a shaft projecting fromthe slender. front thereof.

Another object of the invention is to providedn an elongateddrilla feedof high pressure fluid from the rear end. to a motor at the. front eridwith exhaustthrough the center of the elongated handle to the rearof thedrill wherein the. motor is mounted in. the. nose with antifrictionbearingseachside ofthe impeller of the motor to reduce vibrationyetv toprovidev av relatively high torque.-

A still further object of the invention is to .provide in aminiature.elongated hand drill, a motor housing with a fluid driven turbine.element mounted with antifriction bearings to each side. thereof in thehousing andwherein the housing .has a slotted passage to the turbine.for high pressurev fluid and a slotted passage from the turbine. for lowpressure fluid exhausted therefrom with a surrounding nose cap toenclose the slotted passages.

A further object of the invention is to provide in an elongated handdrillan assembly; of -.outer-casin-g with a nose piece, a centralhollow. insert-ca1;rying a motor assembly at its front end with theinsert received in the rear end of this outer-casing-andlocked in .thecasing from rear end assembly with-fluidpressuresupply being. provided'at the-rear-and-themain lowpressure exhaust also provided forat therear.

Still further objects and the entire scope of applicability of thepresent invention will become apparent from the detailed descriptiongiven hereinafter. It should be understood, however, that the detaileddescription and specific example is given by way of illustration onlyand, while indicating preferred embodiments of the invention is notgiven by way of limitation, since various changes and modificationswithin the spirit and scope of the invention will become apparent tothose skilled in the art from this detailed description.

For a more complete understanding of the nature and scope of theinvention reference is made to the following description and claims andthe drawing in which:

FIG. 1 is a longitudinal cross sectional view of the drill;

FIG. 2 is a cross sectional view of the forward motor end on an enlargedscale;

FIG. 3 is a view along line 3-3 of FIG. 1 showing the rear end of thecenter insert in the outer casing;

FIG. 4 is a view along line 44 of FIG. 1 showing the high pressuresupply and low pressure exhaust to the turbine; and

FIG. 5 is an elevational view of a high pressure conductor fittingreceived in the rear end of the casing and communicating with the centerinsert therein.

Throughout the description like reference numbers refer to similarparts.

This miniature drill is of a size approximately six inches long and witha one-half inch diameter at its main finger grasping portion which issuitably knurled. While this is termed of a miniature type it is ruggedand 3 83 ,946 Patented Apr. 2, I 19163.

2: has ma'nyuses inrthe dental, surgical and even industrial fields.

The drill 10, comprises .in general an.elongated outer tubular casing12,,a nosemember- 14, having a tail piece, an inner elongatedtubularmember 18 carrying in suitable bearings 19 and -20 at its forward endafluid motor generallyindicatedat M which drives shaft 22that maycontain or have attached a chuck. High pressurefluid, such as compressedair, is supplied at'thetail end and passes to the motor M through anannular elongated fluid pressure. passage between outer casing 12 andinner tubular member 18 and exhausts from the motor M mainly throughthecenter of member.18 and towards and through the rear portion 18a ofthe tubular member 18.

'Theouter tubular casing..12 has a main'bodyportion at 12a extendingwith a uniformjdiameter for about twothirds of its length while itsrearor tail end 12a! is of an enlarged diameter, hasan internal shoulder12b. and an internal threaded rear end at to receive thetail piece 16.which is externally. threaded to cooperate. therewith. Theoutsijdeofthe main body 12 z is suitably knurled so as to provide afirm gripforthe fingers of the operator. There is fonnedbetween the outer casing 12and the inner tubular member 18 an elongated Jfluid pressure pas- .sage13 Which conducts fluid supply pressurefrom the rear end forward to themotor M.

The nose piece 14 is tapered to a relatively small front apertured 1 end14a and has an internal small forward bore 151b, an enlarged furtherbore whereby a shoulder 14d is formed therebetween. It has afurtherenlarged bore 1142 at its rear end .whichIis internallythreadedwith a right hand thread and has 'a shoulder 14] there. adjacent.

Theinnertubularmember 18 has an attached'forward end portion 24'that isthreadedly attached by a left hand thread tothe rear portion 18a oftubular member 18 Where a shoulder joint is formed at.18b between 1811and 24. This forward. portion 24 has externalportion 24b and 24c fittingwith the bores 1411' and'14c respectively of the noseimember 14. Aboutmidway between the 'endsof the tubular end portion24 is an annular bore24d whose forward end;24b serves as a thrust receiving portion for therear thrust bearing 19. The forward antifriction bearing 20 is receivedin the forward end of member 24. The nose member 14 is received by asoldered or press fit in the casing 12.

There is received in the bearings 19 and 20' the shaft 22. Received onthe center portion of shaft 22 is a turbine wheel 28 having fluid forcereceiving buckets or pockets 28a therein and thrust shoulders 22a and22b for abutment against the adjacent faces of the inner races of thebearings 19 and 20 respectively.

In the member 24 there is drilled a high pressure fluid supply orifice30 and an elongated slotted passage 30a in the outside of member 24connects the annular passage 13 wit-h the orifice 30 to supply fluidpressure to drive the turbine 28 of the motor M. Exhaust from the motorM is through an exhaust opening 31 in the member 24 and angularlydisposed from supply orifice 30, see FIG. 1, and a slotted passage 32formed in the outside of member 24 connects exhaust opening =31 with anaperture 33 leading also through member 24 to the interior low pressurechamber 24d therewithin. This low pressure chamber 24d communicates withthe low pressure elongated passage 18c in inner tubular member 18 andconducts the exhaust to the rear.

In FIG. 5 there is shown a high pressure fluid conductor fitting 34which has a high pressure fluid conduit 35 with a rear coupler portion35a and a circular plate 33 where the forward end of 35 is soldered intoan aperture 36a in the plate at the outer radial portion thereof. Abrace member 37 connects plate 36 with a second smaller rear plate 38which interconnects 35 and 37. Attached to the front face of plate 36 isa line up pin 36b positioned at a radial distance out from the platescenter and which is received in an aperture 39a in a flange member 39attached to the rear end of the inner tubular member 18.

The rear end 12d of the outer casing at 12 receives the flanged end 39which is formed with a shoulder 3% so as to receive a sealing O-ring 40.Through the flanged end 39 there extends an aperture 390 which lines upwith and receives fluid supply pressure from the conduit 35. Anotherline up .pin 39d projects to the rear from flange portion 39 and extendsthrough a mutable line up the aperture in plate 36. A suitable gasket 42is disposed between the flange portion 39 and the plate 36 on fixture34.

It will be noted in FIG. 4 that the surrounding interior poi-tion of thenose member 14 cooperates with the slots 30:: and 32 in member 24 toform the high pressure and low pressure passages.

The shaft 22 may be hollow all the way from end to end and may have amutable plastic line in its front end to receive a cutting tool.

This drill is light weight yet is rugged and develops a relatively hightorque and operates at speeds of about 400,000 r.p.m. It has been foundto be highly useful in dental surgery.

I claim as my invention:

1. A drill comprising, in combination, an elongated outer tubularhousing having a rear end and a forward end, said forward end havingconnecting means for receiving the rear end of a nose member, an innerelongated tubular member having connecting means at its rear end forconnecting with the surrounding rear end portion of the outer housing,said inner tubular member being radially spaced from the surroundingouter housing thereby providing an annular elongated fluid pressurepassage therebetween, said inner tubular member having its forward endprojecting beyond said outer tubular housing and seated in the nosemember, means detachably securing said inner tubular member to the rearportion of the nose member and a rear thrust bearing receiving recess, athrust bearing received in the thrust bearing receiving recess, aforward bearing received in the forward end of said inner tubular memberand spaced from the rear bearing, a drill shaft received in andextending through said bearings and projecting outwardly in the forwardend of said nose member, an annular turbine rotor fixed to said shaftintermediate said bearings and having thrust engaging portions thereonfor engaging said bearings, said forward end of the inner tubular memberhaving a high pressure fluid orifice therethrough adjacent said turbineand an exhaust orifice angularly spaced therefrom, a passage means inthe inner tubular member conecting the high pressure orifice with theannular elongated fluid pressure passage, a second passage means in theinner tubular member connecting the exhaust orifice and the inner cavityin the inner tubular member for exhausting fluid from the turbine.

2. A drill according to claim 1 wherein said inner tubular member has aforward portion carrying said means for attaching the same to thesurrounding nose member and a rear portion having attaching means forjoining to the rear of the forward portion, whereby to provide easyassembly through the rear end of the drill.

3. A drill according to claim 2 wherein the means attaching the forwardportion of the inner tubular member includes threads and wherein themeans attaching the forward portion to the rear portion of the innertubular member includes threads of an opposite hand to said firstmentioned threads.

4. A drill according to claim 1 wherein said connecting means at therear end of said inner tubular member comprises an annular shoulderportion in the rear end of the outer tubular housing, an annular flangedportion on the rear end of the inner tubular member having an annularshoulder portion thereon and gasket sealing means between said shoulderportions, said annular flanged portion on the rear end of the innertubular member having high pressure fluid passage means thereincommunicating with said elongated annular high pressure fluid supplypassage to said turbine.

References Qited in the file of this patent UNITED STATES PATENTS1,163,642 Darlington Dec. 14, 1915 1,167,997 Haver Jan. 11, 19162,128,157 Monnier et al Aug. 23, 1938 2,591,488 Yost Apr. 1, 1952

1. A DRILL COMPRISING, IN COMBINATION, AN ELONGATED OUTER TUBULARHOUSING HAVING A REAR END AND A FORWARD END, SAID FORWARD END HAVINGCONNECTING MEANS FOR RECEIVING THE REAR END OF A NOSE MEMBER, AN INNERELONGATED TUBULAR MEMBER HAVING CONNECTING MEANS AT ITS REAR END FORCONNECTING WITH THE SURROUNDING REAR END PORTION OF THE OUTER HOUSING,SAID INNER TUBULAR MEMBER BEING RADIALLY SPACED FROM THE SURROUNDINGOUTER HOUSING THEREBY PROVIDING AN ANNULAR ELONGATED FLUID PRESSUREPASSAGE THEREBETWEEN, SAID INNER TUBULAR MEMBER HAVING ITS FORWARD ENDPROJECTING BEYOND SAID OUTER TUBULAR HOUSING AND SEATED IN THE NOSEMEMBER, MEANS DETACHABLY SECURING SAID INNER TUBULAR MEMBER TO THE REARPORTION OF THE NOSE MEMBER AND A REAR THRUST BEARING RECEIVING RECESS, ATHRUST BEARING RECEIVED IN THE THRUST BEARING RECEIVING RECESS, AFORWARD BEARING RECEIVED IN THE FORWARD END OF SAID INNER TUBULAR MEMBERAND SPACED FROM THE REAR BEARING, A DRILL SHAFT RECEIVED IN ANDEXTENDING THROUGH SAID BEARINGS AND PROJECTING OUTWARDLY IN THE FORWARDEND OF SAID NOSE MEMBER, AN ANNULAR TURBINE ROTOR FIXED TO SAID SHAFTINTERMEDIATE SAID BEARINGS AND HAVING THRUST ENGAGING PORTIONS THEREONFOR ENGAGING SAID BEARINGS, SAID FORWARD END OF THE INNER TUBULAR MEMBERHAVING A HIGH PRESSURE FLUID ORIFICE THERETHROUGH ADJACENT SAID TURBINEAND AN EXHAUST ORIFICE ANGULARLY SPACED THEREFROM, A PASSAGE MEANS INTHE INNER TUBULAR MEMBER CONNECTING THE HIGH PRESSURE ORIFICE WITH THEANNULAR ELONGATED FLUID PRESSURE PASSAGE, A SECOND PASSAGE MEANS IN THEINNER TUBULAR MEMBER CONNECTING THE EXHAUST ORIFICE AND THE INNER CAVITYIN THE INNER TUBULAR MEMBER FOR EXHAUSTING FLUID FROM THE TURBINE.